It is therefore the greatest mistake to imagine that the semen is something to be got rid of frequently all the vital energy and the precious chemical substances which go to its composition can be better utilised by being transformed into other creative work on most days of the month. And so mystic and wonderful are the chemical transformations going on in our bodies that the brain can often set this alchemy in motion, particularly if the brain is helped by knowledge. A strong will can often calm the nerves which regulate the blood supply, and order the distended veins of the penis to retract and subside without wasting the semen in an ejaculation.

But while it is good that a man should be able to do this often, it is not good to try to do it always. The very restraint which adds to a man's strength up to a point, taxes his strength when carried beyond it. It is my belief that just sufficient restraint to carry him through the ebb-tides of his wife's sex-rhythm is usually the right amount to give the best strength, vigour, and joy to a man if both are normal people. If the wife has, as I think the majority of healthy, well-fed young women will be found to have, a fortnightly consciousness or unconscious potentiality of desire, then the two should find a perfect mutual adjustment in having fortnightly unions; for this need not be confined to only a single union on such occasion. Many men, who can well practise restraint for twelve or fourteen days, will find that one union only will not then thoroughly satisfy them; and if they have the good fortune to have healthy wives, they will find that the latter, too, have the desire for several unions in the course of a day or two. If the wave-crests facing page 32 are studied, it will be seen that they spread over two or three days and show several small minor crests. This is what happens when a woman is thoroughly well and vital; her desire recuri during a day or two, sometimes even every few hours if it does not, and sometimes even when it does, receive satisfaction.

Expressed in general terms (which, of course, will not fit everybody) my view may be formulated thus : The mutually best regulation of intercourse in mar-mge is to have three or four days of repeated unions, followed by about ten days without any unions at all, unless some strong external stimulus has stirred a mutual desire.

I have been interested to discover that the people known to me who have accidentally fixed upon this arrangement of their lives are happy : and it should be noted that it fits in with the charts I give which represent the normal, spontaneous feeling of so many women.

There are many women, however, who do not feel or who may not at first recognise, a second, but have only one time of natural pleasure in sex in each moon-month. Many men of strong will and temperate lives will be able so to control themselves that they can adjust themselves to this more restrained sex-life, as do some with whom I am acquainted. On the other hand, there will be many who find this period too long to live through without using a larger amount ol energy in restraining their impulse than is justifiable It seems to me never justifiable to spend so much energy and will power on restraining natural impulses, that valuable work and intellectual power and poise are made to suffer. If, then, a strongly-sexed husband who finds it a real loss to his powers or work to endure through twenty-six days of abstinence, should find himself married to a wife whose vitality is so low that she 'can only take pleasure in physical union once in her moon-month (in some it will be before, in some a little time after, her men-•strual flow), he should note carefully the time she is spontaneously happy in their union, and then at any cost restrain himself through the days immediately following, and about a fortnight after her time of desire he should set himself ardently to woo her. Unless she is actually out of health he is more likely then than at any other time to succeed not only in winning her compliance, but also in giving her the proper feeling and attaining mutual ecstasy.

The husband who so restrains himself, even if it is hard to do it, will generally find that he is a thousand-fold repaid not only by the increasing health and happiness of his wife, and the much in-tenser pleasure he gains from their mutual intercourse, but also by his own added vitality and sense of self-command. A fortnight is not too long for a healthy man to restrain himself with advantage.

*Sir Thomas Clouston says (" Before I Wed," 1913, page 84): " Nature has so arranged matters that the more constantly control is exercised the more easy and effective it becomes. It becomes a habit. The less control is exercised the greater tendency there is for a desire to become a craving of an uncontrollable kind, which is itself of the nature of disease, and means death sooner or later." This conclusion is not only the result of the intellectual and moral experience of our race, but is supported by physiological experiments.

While a knowledge of the fundamental laws of our being should in the main regulate our lives, so complex are we, so sensitive to a myriad impressions, that clock-work regularity can never rule us.

Even where the woman is strongly sexed, with a well-marked recurrence of desire, which is generally satisfied by fortnightly unions, it may not infrequently happen that, in between these periods, there may be additional special occasions when there springs up a mutual longing to unite. These will generally depend on some event in the lovers' lives which stirs their emotions; some memory of past passion, such as an anniversary of their wedding, or perhaps will be due to a novel, poem, or picture which moves them deeply. If the man she loves plays the part of tender wooer, even at times when her passion would not spontaneously arise, a woman can generally be stirred so fundamentally as to give a passionate return. But at the times of her ebb-tides the stimulus wili have to be stronger than at the high tides, and it will then generally be found that the appeal must be made even more through her emotional and spiritual nature and less through the physical than usual.